From: Toni Wilen <twilen@winuae.net>
Date: Sat, 25 Mar 2017 17:24:20 +0000 (+0200)
Subject: Check overrun even if whole line is emulated in single pass. Check for extremely... 
X-Git-Tag: 3500~76
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=42a686a6fd4f869ebe36e53ded76504c9764d311;p=francis%2Fwinuae.git

Check overrun even if whole line is emulated in single pass. Check for extremely wide overrun line lengths and limit to sane size.
---

diff --git a/custom.cpp b/custom.cpp
index 930fa761..30e726fc 100644
--- a/custom.cpp
+++ b/custom.cpp
@@ -1301,8 +1301,9 @@ static void update_toscr_planes (int fm)
 
 STATIC_INLINE void maybe_first_bpl1dat (int hpos)
 {
-	if (thisline_decision.plfleft < 0)
+	if (thisline_decision.plfleft < 0) {
 		thisline_decision.plfleft = hpos;
+	}
 }
 
 static int fetch_warn (int nr, int hpos)
@@ -2364,6 +2365,9 @@ static void finish_final_fetch (void)
 	
 	// This is really the end of scanline, we can finally flush all remaining data.
 	thisline_decision.plfright += flush_plane_data (fetchmode);
+	// This can overflow if display setup is really bad.
+	if (out_offs > MAX_PIXELS_PER_LINE / 32)
+		out_offs = MAX_PIXELS_PER_LINE / 32;
 	thisline_decision.plflinelen = out_offs;
 
 	finish_playfield_line ();
@@ -2740,7 +2744,7 @@ static void decide_fetch (int hpos)
 
 STATIC_INLINE void decide_fetch_safe (int hpos)
 {
-	if (!blitter_dangerous_bpl) {
+	if (!blitter_dangerous_bpl && !bitplane_overrun) {
 		decide_fetch (hpos);
 		decide_blitter (hpos);
 	} else {
@@ -3700,6 +3704,10 @@ static void finish_decisions (void)
 	if (nodraw ())
 		return;
 
+	// if overrun at the beginning of scanline was not handled: do it here first.
+	if (bitplane_overrun) {
+		do_overrun_fetch(hpos, fetchmode);
+	}
 	decide_diw (hpos);
 	decide_line (hpos);
 	decide_fetch_safe (hpos);
diff --git a/drawing.cpp b/drawing.cpp
index fd88ac3b..734a4ace 100644
--- a/drawing.cpp
+++ b/drawing.cpp
@@ -1002,6 +1002,8 @@ static void pfield_init_linetoscr (bool border)
 
 	/* Now, compute some offsets.  */
 	ddf_left -= DISPLAY_LEFT_SHIFT;
+	if (ddf_left < 0)
+		ddf_left = 0;
 	pixels_offset = MAX_PIXELS_PER_LINE - (ddf_left << bplres);
 	ddf_left <<= bplres;
 
@@ -1033,8 +1035,11 @@ static void pfield_init_linetoscr (bool border)
 	if (linetoscr_diw_end > native_ddf_right) {
 		int pos = res_shift_from_window (native_ddf_right - native_ddf_left);
 		int size = res_shift_from_window (linetoscr_diw_end - native_ddf_right);
+		if (pos + size > MAX_PIXELS_PER_LINE)
+			size = MAX_PIXELS_PER_LINE - pos;
+		if (size > 0)
+			memset (pixdata.apixels + MAX_PIXELS_PER_LINE + pos, 0, size);
 		linetoscr_diw_start = native_ddf_left;
-		memset (pixdata.apixels + MAX_PIXELS_PER_LINE + pos, 0, size);
 	}
 }
 
@@ -1048,7 +1053,10 @@ static void pfield_erase_hborder_sprites (void)
 	if (sprite_last_x > native_ddf_right) {
 		int pos = res_shift_from_window (native_ddf_right - native_ddf_left);
 		int size = res_shift_from_window (sprite_last_x - native_ddf_right);
-		memset (pixdata.apixels + MAX_PIXELS_PER_LINE + pos, 0, size);
+		if (pos + size > MAX_PIXELS_PER_LINE)
+			size = MAX_PIXELS_PER_LINE - pos;
+		if (size > 0)
+			memset (pixdata.apixels + MAX_PIXELS_PER_LINE + pos, 0, size);
 	}
 }